I have been reading books such as The Gravity Well for well over 25 years. All of them seek to enthuse readers with the desire to pursue an aggressive spaceflight program, both human and robotic, and to realize what the authors envision as spaceflight’s primary objective in colonizing other worlds. And author Stephen Sandford, working with Jay Heinrichs, has done a creditable job of making this case. They will not convince anyone not already leaning toward support but they provide ample evidence and effective argument on why this objective is both worthwhile and attainable. They are to be applauded for that accomplishment. So many other books of this type utterly fail to demonstrate the significance of spaceflight even for those of us already predisposed to accept the argument.

Sandford and Heinrichs begin with a simple assertion: the problem of gravity forces humans to live at the bottom of an ocean of air and shedding that environment is no less difficult than that of the first sea creatures crawling onto the shore and entering the next stage of evolution. They insist that conquering that “gravity well” offers the fundamental promise of human survival. Not to succeed in this task means the human race will become extinct. The best case scenario is that several billion years in the future the Sun will become a red giant and consume the whole of the solar system, but there are also more immediate threats. There is every reason to believe that an Earth-striking asteroid or comet could destroy most of the life on Earth at some point in the future. The K-T event is generally viewed as an impact that wiped out the dinosaurs, leading SF writer Larry Niven to quip: “The dinosaurs became extinct because they didn’t have a space program. And if we become extinct because we don’t have a space program, it’ll serve us right!”

In eleven succinct chapters Sandford and Heinrichs discuss where humanity is today when it comes to space exploration—and when I say humanity I mean Americans since that is the concentration of the authors—and what might the future hold. They focus on what it takes to overcome the “gravity well” and to become a multiplanetary species. They are enamored with the rise of new firms such as SpaceX and Blue Origins and Bigelow Aerospace. They emphasize the rise of a “space economy,” which is a meme that has resonance in NASA and among others in the aerospace community but nowhere else.

They celebrate the tackling of impressive technological feats, such as the landing of a reusable first stage after undertaking a supply mission to the International Space Station. They insist that space is the centerpiece of a bright future for the United States. The economy will flourish, the people of the nation and the world will be inspired, and it will—to use catch phrase coined for a different purpose—help “make America great again.” This sentiment, if not the actual words, is to be found everywhere in The Gravity Well.

Some of the arguments made by the authors are well laid out and quite effective. Sandford and Heinrichs eloquently restate the problem of not enough Americans entering professions focused on science, technology, engineering, and mathematics (STEM). No question, there are innumerable studies about the dearth of engineers, etc., being produced by American universities. That is the case despite the fact that the U.S. government funnels $4.3 billion every year into STEM education and related initiatives. Might space exploration help in this arena? Yes, at least to some degree. School children may become jazzed by what they see happening and pursue careers that further space activities. There is evidence of this in the past; there will continue to be evidence of it in the future. But the critical determinant for whether or not a student pursues a scientific or technical degree in college is whether or not they were successful before college in learning algebra, calculus, geometry, and trigonometry. Inspiration is one part of the equation; but teaching these capabilities more effectively is critical as we move forward.

The authors, to their credit, poke holes in the sophomoric “spinoff” argument used by NASA to justify investment in spaceflight. There are, of course, commercial products that emerge from NASA research and development. It is virtually impossible, however, to draw a straight line between an investment made by NASA in something used in spaceflight and some commercial product. I think the authors would agree that this argument is not effective as presently made by most in the space agency. The problem is that no amount of cost-benefit analysis, which the spinoff argument essentially makes, can sustain NASA’s historic level of funding.

More useful, I would assert, is a counterfactual question. How would life today be different if there were no space program? There can be no fully satisfactory answer to that question. But perhaps we can begin with the elimination of a great many of the space-based capabilities that have changed our lives. Both Sandford and Heinrichs note that to accomplish the larger space program there had to be a push of technological development in certain paths that might have not been followed otherwise. This has made a difference in modern society.

The authors are on less firm ground when they make some other arguments. For example, they suggest that the American economy grew faster in the 1960s than either in the 1950s or the 1970s. They assign the reason for this to the expansive space program of the Apollo era. This is a superficial assertion at best. First, for all three decades U.S. GDP was relatively stable with annual growth between 2.5 and 5 percent. There were ups and downs, certainly, but there does not seem to be a lot different between the decades. Second, were any changes really the result of investment in spaceflight? Perhaps some but not too much, it was simply too small a percentage of the total economy to make much of a difference.

Overall, this is a useful book, especially for those convinced of the value of spaceflight who wish to hone their skills in persuading others with cogent analysis and presentation. For those involved in spaceflight, what is presented in The Gravity Well will probably not seem very original. We have all heard these arguments many times. Many of those times, however, the arguments have not been as well made as here.